1. Field of the Invention
The present invention relates to a method of aligning form data (profile data), which is obtained by a form measuring instrument, an image measuring instrument, a three-dimensional measuring instrument, and the like, and a form measuring device using the method.
2. Description of the Related Art
Conventionally, there have been known various form measuring devices which measure a three-dimensional form of an object to be measured (hereinafter, “measured object”) in a noncontact manner using an optical system. Known examples of a form measuring device, which enables three-dimensional measurement of a measured object having a minute unevenness such as a micromachine and an LSI, include a white light interferometer. The white light interferometer applies white light from a white light source to a measured object and a reference surface to interfere white lights reflected from the measured object and the reference surface. The white light interferometer moves the reference surface in an optical axis direction to detect a reference surface position having the highest interfering light intensity, thereby to measure the height in the optical axis direction of the measured object based on the reference surface position (International Publication WO 2006/068217).
However, in the above conventional form measuring device, if a measured object having unevenness is measured as in line-width measurement of an IC package, there is a problem that data in the uneven portion is likely to have defect. If data has defect, stable and highly accurate measurement results cannot be obtained.
In view of the above problems, an object of the invention is to provide a form measuring device, which suppresses the influence of data defect in an uneven portion and can obtain stable and highly accurate measurement results, and a method of aligning form data.